Women who are close to retirement significantly underestimate the amount of money they’ll have to spend out-of-pocket in retirement to cover health care costs, according to a new report.

Nationwide Financial, Columbus, Ohio, published this finding in a summary of results from a new survey, “Health Costs in Retirement: Consumer Study.” The online survey, conducted by Harris Interactive on behalf of Nationwide Financial in January, polled 625 adults (including 215 women) ages 55+ having $250,000 or more in household assets who plan to retire by 2020; plus 625 adults ages 65 and older having $250,000 or more in investable assets.

The women polled say they will spend $4,624 each year on health care beyond what Medicare covers. That’s 21% less than the $5,882 men nearing retirement estimate they will spend each year on things like premiums, copayments and deductibles.

However, a 2012 study found that a 65-year-old couple retiring today would need $240,000 (not including long-term care costs) to cover medical expenses during their retirement years.

According to the survey, nearly half of both women and men say they are “terrified” of what health care costs may do to their retirement plans. Yet, women respondents nearing retirement are much more likely than men respondents to say they have not estimated:

How much they will spend each year in retirement on things like premiums, copayments and deductibles (41% vs. 27% of men)

How much income in retirement they will have from things like Social Security, retirement accounts or pensions (21% vs. 12% of men)

On average, women estimate that Medicare will cover 65 percent of their annual health care costs. But, similar to male respondents, when asked how they came to this percentage, 85% either guessed or did not know. Only 2% said they were told this by a financial advisor.

Women are also slightly more likely than men to say they are somewhat unconfident to not at all confident in their plan to live comfortably in their retirement years (46% vs. 39% of men).

While 65% of women have discussed their retirement with a financial advisor, of those who have, only one in 10 talked about how much they should expect to pay in health care costs apart from Medicare (compared to one in four men).

Of those who have discussed retirement with a financial advisor, 77% of women say they were helpful to very helpful estimating health care costs in retirement (63% of men). And more than 8 in 10 (86%) say they were helpful to very helpful discussing the role Medicare will play in their retirement (52 percent men).